How to Fix a Non-System Disk or a Disk Error on a Computer

By Candace Benson

Windows operating systems may show a "Non-system disk or a disk error" message when booting up the computer. The reasons for this error message vary, and the time and money that you may have to spend to fix the problem will depend upon the cause. If you have been using your computer for some time, your hard disk may be failing or you may have inadvertently changed settings. If you've just installed the disk drive, check your internal connections and reinstall the drive according to the hard drive manufacturer's installation instructions.

Step 1

Remove any floppy disks or bootable CDs, DVDs, USB flash drives or other bootable media from the computer. Attempt to restart the computer again. Proceed if you continue to receive the error.

Step 2

Restart the computer again. Press the key required to enter your BIOS setup. (The monitor usually displays a "Press [key] to access BIOS" right after restarting your computer. Press the key shown on your screen.)

Step 3

Navigate to the "Boot Options" or "Advanced" menu by using the arrow keys. (The precise menu terms will vary according to your computer and BIOS type.)

Step 4

Select the hard disk that contains your operating system (usually C:) as your primary boot device. Select your CD/DVD drive, your floppy drive or another hard disk as your secondary boot device.

Step 5

Save and exit the BIOS. Proceed with the next step if you see the "Non-system disk error" message again.

Step 6

Restart the computer. Return to the BIOS' "Boot Options" screen by following the steps above, then set the "CD/DVD drive" as the primary boot device and the hard disk as the secondary boot device. Save and exit the BIOS.

Step 7

Insert your Windows installation disc. Restart the computer. Press any key to boot from disc. Follow the on-screen prompts to reinstall Windows.

Step 8

Replace your hard disk drive if you cannot install Windows.

Tips & Warnings

  • Test your hard disk through the BIOS if your BIOS supports this feature.